In view of the fact that the Ney-e Haftband is the only wind tradition in classical Persian music, the lack of attention paid to it in previous scholarly studies is rather surprising. This dissertation is a study of the Persian ney and its music as it emerged in the city of Esfehan during the nineteenth century.It provides a comprehensive body of information related to the structure of the instrument, its playing techniques, and its use in current musical practices. It discusses the development of the Persian technique by Nayeb Assdollah, the famous ney player of the Nasseri court, and how his new technique of sound production, the 'tooth and lip' technique, provided possibilities for development and change in the musical style of the ney. An extended section discusses the role of Ostad Hassan Kassai in the dissemination of current musical practices on the ney. Kassai's ideas and concepts about poetry and musical pulse have established definite styles in the tradition of ney playing and have resulted in the incorporation of many elements from both vocal music and the music of string instruments.The second section of the study includes an analytical discussion of 17 performances of classical Persian music by four of Iran's current ney players. It also includes a few performances by some former musicians in order to cover earlier trends in the practice of the ney. The performances are from the dastgahs of Shur, Segah, Mahur, and Chahargah. The analyses cover the choice of gushes and how these choices are affected by their adaptability to the specific characteristics of the ney. The dominant and principal gushes of each performance are transcribed in an attempt to understand how the musical content of each gushe compares or contrasts to its original form in radif books.The study has found that the structure of the ney does determine to a large extent, the process of improvisation and the selection of gushes in performances. However, despite substantial variety, improvisations on the ney are found to be compatible with the practice of radif on other instruments, and that previous assumptions regarding an autonomy in the radif of ney is not valid. Moreover, the use of gushes and the specific roles assigned to them coincide, for the most part, with their traditional use in radif books. In conclusion, the study has determined that the music of the ney belongs to a musical system which stresses individual traditions, but at the same time is unified by closely related structures and symbols.